Wipers Inoperative

With ignition switch on and wiper switch off, ground test light and touch probe to wiper terminal No. 2. See Fig 1 . If test light is off, check and replace fuse if necessary. If fuse blows again, check for short in wire to terminals No. 2 and 5, or motor for high amperage draw. If test light is on, go to step 2).

Fig 1: Testing Wiper Terminal
Courtesy of GENERAL MOTORS CORP.
Touch probe to wiper terminal No. 1. See Fig 1 . If wipers run, check for open circuit in wire between terminal No. 1 and wiper switch. Check wiper switch. If wipers do not run, go to step 3).
With wiper switch in low, touch probe to terminal No. 6. See Fig 2 . If wiper runs, check for open circuit in wire between terminal No. 6 and wiper switch. Check wiper switch. If wiper does not run, go to step 4).

Fig 2: Testing Wiper Motor Terminal No. 6
Courtesy of GENERAL MOTORS CORP.
Remove washer pump cover and attach wiring to wiper. With wiper switch in low, ground test light and touch probe to terminal of Red wire at pulse relay. See Fig 3 .
If test light is off, check connection to wiper terminal No. 1. Check for open in Red wire. If no open is found, replace park relay. If test light is on, go to step 6).

Fig 3: Testing Wiper Motor Pulse Relay
Courtesy of GENERAL MOTORS CORP.
With test light still grounded, touch probe to terminal of Orange wire at pulse relay. If wiper runs, replace timing circuit board assembly. If wiper does not run, go to step 7).
Touch probe to terminal of Black/Pink tracer wire at pulse relay. If test light is off, replace pulse relay. If test light is on, repair wiper motor.